Structure of Ionic Solids - AP Chemistry

Energy required to separate one mole of an ionic solid into gaseous ions. Measures strength of ionic bonding in crystal lattice.

Al^{3+} and O^{2-}. Trivalent cation and divalent anion create very strong lattice.

Octahedral. Six-fold coordination creates octahedral geometry around each ion.

1. Each $Cs^+$ surrounded by 8 $Cl^-$ in cubic coordination.

Electrostatic attraction. Coulombic forces between positive and negative charges.

1. Rock salt structure with octahedral coordination geometry.

Strength of ionic bonds. Stronger ionic bonds create harder, more resistant materials.

Vibrational energy of ions. Higher kinetic energy causes increased lattice vibrations.

Mg^{2+} and O^{2-}. Divalent cation and anion create strong electrostatic attraction.

Rigid and brittle. Fixed ionic positions create inflexible crystal structure.

NaCl. Equal numbers of monovalent cations and anions.

Na^{+} and O^{2-}. Two monovalent cations with one divalent anion.

$Sr^{2+}$ and $Cl^{-}$. One divalent cation with two monovalent anions.

1. Similar structure to NaCl with octahedral coordination.

Crystal lattice. Regular three-dimensional arrangement of cations and anions.

1. Face-centered cubic packing maximizes coordination number.

Lattice energy = $k \frac{Q_1Q_2}{r}$. Energy proportional to charge product, inversely proportional to distance.

Higher charges increase lattice energy. Lattice energy proportional to product of ionic charges.

1. Each $Na^+$ is surrounded by 6 $Cl^-$ ions in rock salt structure.

Ionic solid. Contains $Mg^{2+}$ and $O^{2-}$ ions held by ionic bonds.

A crystalline solid composed of ions held together by electrostatic forces. Cations and anions arrange in repeating three-dimensional patterns.

Body-centered cubic structure. Simple cubic arrangement due to similar ionic sizes.

High melting and boiling points. Strong electrostatic forces require significant energy to overcome.

Smaller ions increase melting point. Smaller ions pack more tightly, requiring more energy to separate.

$Ca^{2+}$ and $Br^{-}$. One divalent cation with two monovalent anions.

Ions must be free to move. Requires molten state or aqueous solution for ion mobility.

Polarity. Polar water molecules can surround and solvate ionic charges.

Higher lattice energy decreases solubility. Stronger lattice forces resist dissolution in polar solvents.

Formation of hydrated ions. Water molecules surround separated ions through ion-dipole interactions.